JPS6040994B2 - Plastisol matrix type ink release member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to improved plastisol matrix ink release members suitable for reproduction and so-called "carbon paper" applications.

Description of the Prior Art Over the past several years, there has been a major shift in copying and reproduction technology from full transfer type "carbon papers" to ink release types.

In the full copy type of "carbon paper", carbon particles are suspended in a work medium that is supported on a paper substrate. Writing or impact pressure on the base paper in contact with the paper substrate causes the entire portion of the wax layer corresponding to the writing or typing surface to be transferred to the copy sheet that rests on the wax surface. Because the wax layer is soft, this paper is quite difficult to write on and tends to leave some marks on the paper. Additionally, since this duplicating paper functions by transferring the entire wax coating, the useful life of the paper tends to be shortened. To overcome the above-mentioned problems, ink release type reproductions or "carbon papers" have been developed.

This ink-release type carbon paper is first prepared using a solution or dispersion consisting of a synthetic organic resin, a plasticizer for the resin, a liquid ink vehicle which is also a plasticizer for the resin, and a colorant material. Next, by applying the solution or dispersion onto a suitable substrate and drying,
The solvent is evaporated or a plastisol is formed to form a nucleated resin matrix containing the liquid ink. Because the liquid ink is retained within the matrix, it leaves the surface of the reproduction sheet clean when it comes into contact with the surface. Liquid ink can be removed from the matrix by selectively applying pressure. These partially emptied areas within the matrix are re-accumulated by migration of ink from other areas, thus increasing the useful life of the copy sheet. Replicated sheets made from solutions are described in US Pat.
lph day. CIarN, which patent is assigned to the assignee of the present application.

Copy sheets made from plastisol-forming dispersions are also described by Ralph et al. in U.S. Pat. No. 2,989,493, issued June 20, 1961. Disclosed by CIark. This patent also
Assigned to the assignee of this application. The ink discharge member of the present invention is disclosed in U.S. Patent No. 2,98
No. 9,493, which prior patent is incorporated herein by reference.

The ink transfer compositions disclosed in U.S. Pat. No. 2,989,493 were made from finely divided polyvinyl chloride resin particles dispersed in a liquid organic vehicle containing a dye.

This liquid organic vehicle consists of the following components. namely, a plasticizer that acts to solvate the polyvinyl chloride resin particles by heating to their melting temperature, a thermopolymerizable resin to mix the polyvinyl chloride resin during melting, and a substantially inert resin. It is a mixture with an organic liquid that is dry and usually substantially non-volatile at room temperature. The organic liquid is sufficiently non-adhesive and present in sufficient quantity to be removed from the crushed resin to be displaced when pressure is applied. Additionally, the composition contains small amounts of catalyst, stabilizer and filler. To obtain good writing strength and reasonable longevity from this ink transfer composition, large amounts of organic liquid vehicle are used to support the pigmented material.

To obtain adequate write strength, 25% to 3% by weight oil is required. However, it has been found that the presence of such large amounts of oil makes the melting process difficult. To melt or harden plastisol, 175°C to 2
A temperature in the range of 0.05°C is required. At this temperature, multiple oils emit and leave the coating surface, contaminating the air and thus requiring expensive equipment to remove the oil from the air. As a result, the cost of wasted oil, and therefore the equipment necessary to control it, adds substantially to the cost of producing the ink-transfer member. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an ink transfer member that overcomes the above-mentioned problems.

The ink release member of this invention is an improvement on the ink transfer member disclosed and claimed in the aforementioned U.S. Pat. No. 2,989,493. According to the present invention, air pollution can be reduced or substantially eliminated by reducing the amount of emitted oil from conventional tanks, and the oil can be converted into a substantially water-insoluble and Non-hygroscopic polyglycols can be substituted, which have low viscosity at room or ambient temperature and low vapor pressure at plastisol melting temperatures of 175°C to 205°C, and which also dissolve or disperse coloring materials. can be done. A preferred polyglycol is polypropylene having a molecular weight of about 1000-5000.

This is because compounds with a molecular weight of 1,000 or less tend to be water-soluble, while compounds with a molecular weight of 5,000 or more tend to be solid.

Other polyglycols, such as mixed polyglycols, i.e. polyglycols consisting of one or more polyglycols, also meet the basic requirements that they be substantially non-water soluble and non-hygroscopic, and are soluble at room temperature. It can be used as long as it has a low viscosity, a low vapor pressure at the plastisol melting temperature, and the ability to dissolve or disperse the colored material.
Polyglycols may replace all oil vehicles in plastisol compositions.

The composition may contain about 15% by weight polyglycol, preferably about 5% to 8% by weight polyglycol. Since polyglycols are substantially more expensive than conventional oil vehicles, preferably only amounts sufficient to meet air contamination and adequate oath strength requirements should be used. Therefore, up to 15% by weight of the vehicle for liquid ink is polypropylene glycol as the polyglycol, and the remaining part may be animal oil, vegetable oil, mineral oil, marine oil or synthetic oil, preferably 5 to 8% by weight. A weight percent can be made up of polypropylene glycol and the remainder made up of animal, vegetable, mineral, marine or synthetic oils.

Furthermore, up to 15% of the vehicle for liquid ink is a mixture consisting of at least one polyglycol and oil, and the oil may be animal oil, vegetable oil, mineral oil, marine oil, or synthetic oil. can. The ink ejection member of this invention is of the plastisol type, and the organic synthetic resin is dispersed within a liquid plasticizer.

This liquid plasticizer does not solvate the resin at room temperature. However, the resin can be solvated by heating to a melting temperature of 17,500-20,500°C. An incompatible oil was added to the resin and plasticizer dispersion. This incompatible oil functions as a non-solvent plasticizer for the resin, as well as a liquid vehicle for colored materials such as dyes, pigments, and mixtures of dyes and pigments. In addition, thermally polymerizable resin,
Added to change the physical properties of molten blastisol. Additionally, other ancillary agents such as stabilizers, fillers and catalysts may be added. For a more complete description of ink ejection members, applicants refer to US Pat. No. 989,493. The resins, plasticizers, oils, dyes, pigments, and incidental additives disclosed in this prior patent, along with the steps for preparing, coating, and finishing the ink transfer composition, are incorporated into the present invention. Suitable for use in ink discharge members. In making the ink transfer member of US Pat. No. 2,493, significant fuming and fumes are generated during melting of the plastisol.

Smoking and fuming are caused by incompatible oil plasticizers in the composition. Experiments have shown that this excess of oily material is necessary to give the coating a reasonable useful life, as well as to give the transferred ink sufficient tonal strength. This excess oil is used to compensate for melting process drive downs. Eliminate air pollution caused by oily materials,
or at least substantially reduce, the applicant:
A number of liquid materials in plastisol link release compositions were tested. This experiment showed that oil vehicles cannot be used. Testing of a large number of compounds from various organic chemical classes has led to the conclusion that certain polyglycol materials can be used in place of oil coloring vehicles for ink release applications. Experiments have led to a set of criteria for polyglycols to be effective oil replacements.

That is, first, the polyglycol must be substantially water-insoluble and substantially non-hygroscopic. A low affinity for water is extremely important in order to maintain the surface cleanliness of the ink ejection member and to prevent moisture on the skin from wicking up liquid ink. Also, hygroscopic polyglycols absorb moisture from the air, which causes the liquid ink contained within the plastisol to spread and swell from the matrix, substantially impairing the effectiveness of the ink transfer member. 25q
Polyglycols having a solubility of about 3 grams per 100 grams of water at a temperature of 0.05 m are suitable.

However, polyglycols are either insoluble in water or
Or, it is preferable that it is at least very slightly soluble. The polyglycol also needs to have a low viscosity at room or ambient temperature, so that it can be easily removed from the plastisol matrix upon application of pressure.

If the material has too high a viscosity, flow from the matrix will be inhibited and the writing strength of the ink ejection member will be reduced in turn. 77o F (25o
o), a viscosity in the range of about 70 to 700 centistokes is passed, and 77o F(260)200 to 4
A range of 0.00 centistokes is preferred.

Furthermore, the vapor pressure of the polyglycol should be very low, especially within the melting temperature range of 175qo to 205oo. If the polyglycol does not have a negligible vapor pressure at the plastisol melting temperature, fuming and fumes are eliminated and there is no need to add excess polyglycol to compensate for losses during melting. Dew. One of the more important criteria for selecting a suitable polyglycol is its ability to dissolve and disperse coloring materials.

The selected polyglycols have the function of forming liquid inks together with similarly selected colorant dyes and/or pigments. If the polyglycol is unable to disperse the colored material, it will separate and only the clear polyglycol or tinted polyglycol will be removed from the ink release layer by application of pressure. If not destroyed, the writing strength of the ink release layer will be substantially compromised. A number of compounds were tested in meeting the selection criteria and in arriving at the preferred materials.

For example, liquid halocarbons are commercially available that have low vapor pressure, are insoluble in water, and have low viscosity. This halocarbon lacks the ability to dissolve and disperse selected colorants. Ethylene glycols such as triethylene glycol as well as polyethylene glycols were also tested. These glycols have low vapor pressure, low viscosity, and the ability to dissolve and disperse selected colorants. However, these glycols constituted undesirable ink release members because they are water soluble and hygroscopic and therefore the ink flows out of the matrix and is not fixed on the surface. Preferred polyglycols have the general formula (C3KO)nC3day60,
Polypropylene glycol with a molecular weight in the range of 0,000.

All of the polypropylene glycols were found to meet the above selection criteria and are commercially available. Dow Chemical Company (D
ow Chemical Company) manufactures a range of polypropylene glycols under the designation Polyglycol P, combining numbers to indicate average molecular weight. For example, a preferred polypropylene glycol is polyglycol P2000. Virtually identical polyps.

Pyrene glycol is also available from other commercial sources. For example, propylene glycol 2025 is manufactured by Union Carbide
poration) and corresponds to polyglycol P2000. It has been found that other polyglycols also exist that meet the selection criteria and are acceptable under the criteria.

For example, a triol derived from ethylene and propylene oxide (Tri
ol) is the designation for polyglycol 112-2, which is manufactured by Dow.
It is sold by The Chemical Company and has been found to be a good replacement for oily ink vehicles. It is believed that having a particular chemical formula is not limiting, as long as the polyglycol meets the selection criteria described above. Polyglycols can be used to replace all conventional oil vehicles in ink transfer members.

However, considering the cost of each material, this
This is unlikely to be the desired course. Polyglycols are substantially more expensive than conventional oils and should therefore preferably be used only in amounts necessary to meet or achieve the desired action goal. The following materials are used in making the ink ejection member. Many of these materials are covered by U.S. Pat.
989,493.
1 Polyvinyl chloride Zeon 121 (Won B F Goodrich 121
) (B.F.Wodrich) Zeon 128 B.F.Goodrich Zeon 130×17 P.F.Goodrich QY
NV Union Carbide Corp.
rbideCorp. ) Marvinor VR Uniroyal Corp 50 (Nyen rvi-no] VR50)
(Uniroya) Corp.) FPC654 Firestone F.

Firestone Plastics C
O. )2 Plasticized Oil Dioctylphthalate Dibutyl Phthalate Tricresyl Phosphate Trioctyl Flexol Fiexol (Triethylene Glycol Di-2 Ethyl Butyrate) Union Carnovade Corp. 3 Oil Mineral Oil Peanut Oil Sperm Whale Oil Castor Oleate Oil 4 Colorants Alkaline Blue Paste (4% by weight pigment in key oil) Carbon Black Nigroshine Black (3% by weight base in oleic acid) Milo IJ Blue 5 Additional Additives Shirashi Vanstay 6172 (barium, cadmium) and zinc organic compounds and mixtures of multiple agents)R. T.
Vanderbilt Co. , Inc. , Nor w
alk, Conn. 6 Polyglycol Polyglycol P1200 Dow Chemical Co. Polyglycol P2000 Dow Chemical Co. Polyglycol P4000 Dow Chemical Co. Polyglycol PI12-2 Dow Chemical Co. Propylene Glycol 1025 Union Carbide Corp Propylene Glycol 2025 Union Carbide Corp Substantially insoluble in water, substantially non-hygroscopic, low viscosity at ambient temperatures, and negligible vapor pressure at blastisol melting temperatures. Other polyglycols that meet the above selection criteria of exhibiting a polyhydric acid and having good solubility and dispersing power for dyes and pigments can also be used.

The following examples illustrate compositions used in making ink release members.

Example 1% by weight Zeon 128 5
0.0 Dioctyl phthalate 2
0.0 trioctyl phosphate 0
．． 5 pot oil 8.
o Alkaline blue pigment 6.0 Polyglycol PI12-2 8.
0 White clay 1.5 When creating this ink transfer composition, colorant materials, white clay,
The natural oil and polyglycol are premixed in a roller mill until a homogeneous mixture is obtained.

Also, pinyl chloride in the form of finely divided particles is premixed with dioctyl phthalate, trioctyl phosphate and a solvent-based plasticizer in a moving mixer. The two are combined and mixed in a moving mixer until the resin particles are well dispersed throughout the liquid. After mixing, if the composition is to be used in making an ink transfer member such as "carbon paper," the composition can be applied to a film substrate such as paper or Mylar using any suitable coating equipment. Coating onto synthetic resin films such as A reverse roll coater or a blade coater is suitable for coating the composition. The composition will be melted after coating by heating the composition to a temperature high enough for the solvent-based plasticizer to solvate the resin particles. Melting can be accomplished by passing the coated substrate over a roll heated to a temperature of about 175° to 205°, or by using an infrared lamp. During the melting process, only a small amount of fuming or fumes is produced due to the small amount of mineral oil included in the composition.

By controlling the temperature and time of melting,
This small amount of smoke can be further reduced.
It has been found that the addition of polyglycols eliminates air contamination while improving writing strength and substantially extending the useful life of the ink ejection member.

Polyglycols are believed to be better vehicles for colorant materials compared to previously used oils. Comparative testing of ink ejection members with and without polyglycol in an automatic pudding oven revealed that polyglycol-containing compositions produced darker writing over a longer useful life. It was confirmed that it gives The following are other examples of compositions for making ink transfer members.

The mixing, coating and melting methods are the same as described in Example 1. Example 2 Weight % Zeon 121 resin 42.5
Diphthyl phthalate 10.6 Flexol 30 days IO.
6 Alkaline Blue Paste 23.
0 polyglycol P2000
9.0Vanstay6172
2.0 Nigro Shin Black
3.0 Example 3 Zeon 121 resin
40.0 Dibutyl phthalate
15.0 Flexol 30 days
5.0 Alkaline Blue Paste 20.0 Polyglycol P2000 50Va ship tay6
172 1,0 Nigroshin Black 4.0
Note that in Examples 2 and 3, it is only the added key oil that is mixed with the blue pigment in the alkaline fluid paste.

The compositions of this invention have been described in the context of making coating compositions for use on reproduction media such as paper. Although such an example is a very suitable use of this invention, the compositions of this invention are not limited to such use. Many other types of ink transfer or ink release compositions can be made, such as self-supporting solid particles in ink pads. Numerous modifications, variations, and equivalents to the compositions disclosed herein by way of example will be readily apparent to those skilled in the synthetic resin art, and therefore fall within the scope of the claims. It is something.

Claims (1)

[Scope of Claims] 1. A plastisol matrix type ink ejection member in which liquid ink is suspended within the pores of the matrix, which has a low vapor pressure at the melting temperature of plastisol and a low viscosity at ambient temperature. , substantially insoluble in water;
Liquid polyglycols, which are substantially non-hygroscopic and effective as parting agents for colorant materials, have been used as vehicles for liquid inks; An ink release member having a molecular weight selected from the group consisting of polypropylene glycol and triols derived from ethylene and propylene oxide. 2 The color vehicle for liquid ink has a molecular weight of 1000 to 5000.
The ink release member according to claim 1, which is polypropylene glycol. 3 The color vehicle for liquid ink has a molecular weight of 1000 to 5000.
The ink ejection member according to claim 1, which is a triol. 4 Up to 15% by weight of the vehicle for liquid ink is polypropylene glycol, and the remainder is animal oil, vegetable oil, mineral oil, marine oil or synthetic oil, Claim 2
The ink ejection member described in Section 1. 5. The ink release member according to claim 2, wherein 5 to 8% by weight of the liquid ink vehicle is polypropylene glycol, and the remainder is animal oil, vegetable oil, mineral oil, marine oil, or synthetic oil. 6. Up to 15% of the vehicle for liquid inks is a mixture of triol and oil, said oil being animal oil, vegetable oil, mineral oil, seafood water or synthetic oil, according to claim 3. ink ejection member.